I. Introduction

 

Ball mill is the key equipment for crushing materials after crushing. Ball mills are widely used in the production of cement, silicate products, new building materials, refractory materials, fertilizers, ferrous and non-ferrous metal beneficiation, and glass ceramics, etc., for dry or wet grinding of various ores and other grindable materials.

2. Working principle:

 

The ball mill is a horizontal cylindrical rotating device, driven by an outer gear, two bins, and a grid type ball mill. The material enters the first chamber of the mill uniformly through the feeding device through the feeding hollow shaft. The chamber has a step liner or a corrugated liner, which contains steel balls of different specifications. The rotation of the cylinder generates centrifugal force to bring the steel balls to a certain height. After falling, it has a heavy blow and grinding effect on the material. After the material reaches the rough grinding in the first warehouse, it enters the second warehouse through the single-layer partition board. The warehouse is lined with flat liners and steel balls to further grind the materials. The powder is discharged through the unloading grate to complete the grinding operation.

 

3. Structural features:

 

The ball mill is composed of main parts such as feeding part, discharging part, rotating part, transmission part (reducer, small transmission gear, motor, electric control) and so on. The hollow shaft is made of cast steel, and the inner lining is removable. The large rotary gear is processed by casting gear hobbing. The cylinder is inlaid with wear-resistant liners, which has good wear resistance. The machine runs smoothly and works reliably. According to the material and discharge method, dry ball mill and wet grid type ball mill can be selected.

 

4. System advantages:

 

a. The ED3100 series inverter adopts current vector control. The good low-frequency torque fully meets the requirements of the starting torque of the ball mill and the large load of the ball mill. It also ensures that the equipment runs smoothly under the frequency conversion state to ensure that the motor has Constant power characteristics.

 

b. The soft start of the frequency converter can reduce the impact of the motor starting on the power grid. Use the frequency conversion speed control system to transform the original ball mill drive system to meet the normal operation of the ball mill at low speeds and ensure the normal process control quality. The service life is extended and maintenance is reduced.

 

C. The modified equipment can realize automatic control and has various timely protection functions, which can reduce the failure rate of the motor. Effectively ensure the normal operation of the equipment.

 

5. Control drawings and parameter settings:

 

ED3100-4T1100M's machine site transformation status control chart is as follows:

6. concluding remarks

 

Practice has proved that the ED3100 frequency conversion ball mill drive is very successful, starting and running at low speed very smoothly. With the improvement of users' experience and acceptance of frequency converters, ED3100 frequency conversion has a broader application prospect in ball mills.